I downloaded Armbian_5.38_Debian_stretch_next_4.14.14 for the orangepi-one and startet armbian-config. In dpkg-reconfigure keyboard-configuration I changed the layout to german-german but it has no effect, the layout remains to the international layout (qwerty etc).
I got this "problem" only on a local terminal via HDMI-Monitor and USB-keyboard and not via ssh/putty.
The last one where I did see the keyboard problem was on my Sunvell T95K Pro (TV Box) unser armbian.
I also did use pkg-reconfigure keyboard-configuration, but got US-Keyboard also after a reboot.
I dont know any more if I did try it later via armbian-config, but some reboots/apt-updates later I did get a german keyboard without doing anything else.